CPMS90V for a wharncliffe utility knife- anyone have thoughts on target RC?

Salem Straub

Salem Straub

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Oct 20, 2008
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Doing a batch of these utilities in S90V- I hope some of you who have used this steel much might enlighten me on what you feel the best hardness to shoot for is and why. Please and thanks.

I'm having Bos HT them.
 
I am pretty sure that what I have read on S90V is that 60-61 is about your max hardness. I have some S90V that I am getting ready to send to Peters and that is the hardness I am shooting for.

Phil Wilson's website seamountknifeworks.com has a lot of information about S90V. Look under the articles section. He mentions that he used to HT it to around 56 with still great results.

Good luck
 
update when you decide what to go for and how the edge turns out , I have some similar steels, 3V, S35VN and am curious to what would be good. One thing I know is that annealed S35VN destroys my makita portaband blades in minutes . When I visited that experienced bladesmith he was working with S30V exclusively making everything from bowies to chef knives and folders.
 
I've done 60-61 in a 3-4" blade without problems. My reason for doing so is to max out what the steel excels in. I've tested one of my small s90v blades on different materials (wood, carpet, cardboard, accidental swipe on the shop floor when cutting something :D) and they stood up fine. It won't be fun to finish or sharpen by hand but if max wear resistence floats your boat go for it. Phil Wilson has made fillet knives and other blades with it and IIRC they held up vey well at 60-61. Please post pics when you're done. I like your work!
 
Hey thanks man, I will post a pic or two. Thanks guys for the input, and for the link to Phil Wilson's site- I'd been there before, but not for a while and not about S90V. There was some real good stuff there. Based on what I've found so far, it seems that indeed I will go with 60-61. Mr. Wilson reported that he didn't have problems with reasonable ductility at this hardness, and that at this range wear resistance did outshine S60V.

Thanks again, if anyone else has alternate recommendations, I'd still like to hear them.

Duffy, that S90V sure took the freshness off my saw blade- but it seemed to reach a point at which the blade was still cutting OKish but not getting duller rapidly. I wonder how much more life I'll get out of it...
 
duffy99,

I've been working with S35VN recently and notice that it destroys the bandsaw blades quickly if I push in hard and very quickly if I try to cut a radius. They seem to last much longer for me if I back up on the pressure a little, cut straight, and let the blade do most of the work - takes longer, but worth it in terms of saved bandsaw blades.
 
Tait said:
duffy99,

I've been working with S35VN recently and notice that it destroys the bandsaw blades quickly if I push in hard and very quickly if I try to cut a radius. They seem to last much longer for me if I back up on the pressure a little, cut straight, and let the blade do most of the work - takes longer, but worth it in terms of saved bandsaw blades.
Click to expand...

Thanks, I was probably hogging it like it was 1084 and pushing way to hard .
 
foxx said:
Wouldn't that info be available from Crucible? Just asking..
Click to expand...

Sure I can get the HT data from several places, I was wondering though how knives from this stuff perform off paper.
I seemed to recall reading somewhere comments about S90V performing better in the 56-58 range. However, I'm finding 60 pretty much recommended across the board. I also wanted to see if I'd get any warnings about excessive brittleness at 60-61. At the end of the day though, a knife made from this stuff is designed primarily as a long-wearing cutter, not a bendable/pryable blade.

Really this was a request for tempering temp info. But since Bos will know that, all I have to do is request an RC range.
 
Salem, A range of 58 to 60 is just right for CPM S90V. Much lower than that and a fine edge will tend to roll. Hardness equals strength. This steel is sluggish in the heat treat due to the amount of vanadium. It takes 2150 F and a quick air quench to get an as quenched hardness of 61, 62. Any tempering at all and it drops down pretty quick. I would stay away from the high heat temper, you can pick up hardness but loose corrosion resistance and toughness. You can specify 60, but if you get 58 no problem, performance will be great. As mentioned I have made many fillet knifes with this steel in the past and still make a few. Even on these thin blades I do not have a problem with chipping. The problem is dynamic loads like chopping and have also to be carefull with twisting loads. This is not only 90V, as you know, but is a caution with all SS in the high 50 low 60's RC. Phil
 
Thanks a bunch for the tips, Phil. I appreciate the documents at your site, too.

I sent 'em out today.
 
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